Automatic winding mechanism for wrist watches



g- 14, 1956 H. JUNGHANS ET AL 2,758,489

UTOMATIC WINDING MECHANISM FOR WRIST WATCHES Filed May 15 1951 .0 F S n nl m QOJZ S vnw w u IJAYU A t M v U mm M Z tm H r 0 l m w United States Patent O AUTDMATIC WINDING MECHANISM FOR WRIST WATCHES Helmut Junghans, Schramberg-Sulgen, Kurt von Zeppelin, Schramberg, and Josef Miilier, Schramherg- Sulgen, Germany, assignors, by mesne assignments, to Bulova Watch Company, Inc., New York, Eienne Branch, Bienne, Switzerland, 21 company of Switzer land Application May 15, 1951, Serial No. 226,451 Claims priority, application Germany May 15, 1950 4 Claims. (Cl. 74S1Z) This invention relates to an automatic winding mechanism for wrist watches of the kind comprising an intermediate gearing train operated through a rocker by a winding pendulum capable of to and fro movement.

The primary object of the invention is to provide means whereby the rocker, upon reversal of the movement of the pendulum is actuated with a very minimum of dead movement so that the movement of the winding pendulum is utilized with utmost completeness.

According to the present invention this purpose is accomplished by providing the rocker with two intermeshing gears mounted thereon, one of which gears is in constant mesh with a pinion fast on the winding pendulum while both gears are automatically engageable with a gear of the winding gear train, which last mentioned gear is mounted on a fixed axis in the watch frame.

The mechanism according to the present invention is distinguished from prior automatic winding mechanisms for wrist watches mainly by the feature that the pair of gears is arranged on the rocker, and not as heretofore upon fixed axes in the frame plate of the watch. As a result or" this arrangement, the rocker gears, when the movement of reversal takes place, are moved substantially radially instead of tangentially as in the prior arrangements, towards the next gear of the train, whereby the dead movement, amounting to 30 to 50 in prior arrangements, is diminished.

In the preferred construction according to the present invention, a direct action control device is arranged between the winding pendulum and the rocker in order to move the rocker positively into the new position of engagement upon reversal of the turning movement of the pendulum. This has for its object to prevent the rocker from remaining in any intermediate position which would interrupt the transmission of the drive or in giving rise to idle movement as a result of lagging of the reversal. The said direct action means consists of a resilient control finger mounted on the rocker, the point of which finger cooperates with the pinion fast on the Winding pendulum in such a manner that during the winding movement it rides freely over the pinion teeth while on reversal of the pendulum movement it enters a tooth gap of the pinion and remains there until completion of the reverse movement. In order to transmit powerful actuating impulses to the rocker this may be in the form of a lever with two arms, and the control finger in the form of a plate spring is fixed to the end of the lever remote from the axis of the rocker gear or gears. The reversing gear carried by the rocker is preferably such that two intermeshing gears are journalled on the rocker, one of which is in constant mesh with the pinion fixed on the winding pendulum which gears can be automatically brought into mesh with a gear fixed on the frame plate of the watch, and forming part of the winding gear train.

Further features and advantages of the invention will be seen from the following description of a constructional 2,758,489 Patented Aug. 14, 1956 example, and will be shown in the accompanying drawing and claimed in the claims.

The drawing illustrates, with omission of parts not necessary for the understanding of the invention, a plan view of a preferred construction according to the invention on an enlarged scale.

In the drawing, 1 designates the winding pendulum which can turn about a pivot 2 and has fast thereon a pinion 3 which is in constant mesh with the first rocker gear 4 which latter in turn is in constant mesh with the second rocker gear 5. The said gears 4 and 5 are carried on the rocker 6 which rocks about a pin 7. Either the rocker gear 4 or the rocker gear 5, according to the position of the rocker 6 will engage a transmission gear 8 mounted on an axis fixed in the frame plate 23. The transmission gear 8 is fast to a pinion 9 which engages a gear 10 fast to a pinion 11 which in turn engages a gear 12. To the gear 12 is attached a ratchet spring 13, the nose of which cooperates with the ratchet wheel 14 which is fixed to a drive pinion 15 engaging the gear 16 of the main spring stem. The said pinions and gears constitute the intermediate gearing train through which the pendulum winds the main spring.

As explained in the mode of operation hereinafter, the ratchet spring 13 and the ratchet wheel 14 cannot prevent back running of the gearing, not being adapted for this purpose. Security against back running is obtained by a pawl 17 pivoted at 18 on the frame plate 23, and acted upon by a spring 19 attached to the pawl and bearing at its free end against a pin 20 fixed in the frame plate. The pawl 17 has its nose engaging the transmission gear 8.

To insure that the rocker 6 upon reversal of motion of the winding pendulum 1 will always be operated positively and immediately, the outwardly extending arm 6a of the rocker has attached thereto a control finger 21, by means of a screw 22. The point 21a of the control finger 21 projects into the path of the teeth of the pinion 3 fixed on the winding pendulum 1. The arrangement and dimensions of the control finger 21 are such that its point 21a during the winding rotation of the pendulum 1 is pushed aside by the pinion teeth and rides resiliently over said teeth. At the instant of reversal of the pendulum motion, the point 21a resiliently enters a tooth gap of the pinion 3 and is carried along therewith in the following pendulum movement. The control finger 21 thereby entrains the rocker 6, that is, turns it about its axis 7 until the reverse movement is ended. The point 21a then rises out of the teeth of the pinion 3 and in the following winding rotary movement of the pendulum rides freely and resiliently over the pinion teeth.

The mode of operation of the above described mechanism is as follows:

Automatic winding Assuming that the winding pendulum is turning in clockwise direction, the teeth of the pinion 3 will push the point 21a of the control finger on to rocker 6, 6a forwardly; at the same time, the first rocker gear 4 is moved in the direction of the arrows, and the gear 4 and drive gear 5, gear 8, pinion 9, gear 10, pinion 11, gear 12, pawl spring 13, ratchet spring 14, pinion 15 and spring stern gear 16, each in the direction of the arrows. In this movement the rocker 6 occupies the position shown in full lines in the drawing. Partly by means of the force exerted on the control finger 21 by the teeth of the pinion 3, and partly by the action of the friction of the gears 4 and 5, the rocker 6 will be retained in this position.

When the winding pendulum 1 receives an impulse in counterclockwise direction it first comes to rest, then the point 21a of the control finger 21 will spring into the next tooth gap on pinion 3 Where it will remain during the following pendulum movement, causing the rocker 6 to participate in the movement (in clockwise direction as seen on the drawing) so that it comes into the positionv shown in broken lines. In this position the first rocker gear 4 engages the transmission gear 8 and the second rocker gear 5 runs idly while the point 21a of the control finger 21 lies in the position shown in broken lines, that is, it slides freely over the pinion teeth. The gear 8 is driven in the same direction as are also the following elements of the gear train up to the spring stem gear 16.

During automatic Winding, the pawl 17 prevents unwinding the main spring by back running of the gear; the ratchet mechanism 1 .3, 14 and 15 does not come into operation.

Hand winding Hand winding is effected by means of known parts which for clearness are not shown in the drawing, by means of which the spring stem gear 16 is turned in the direction of the. arrow. The gears and elements 12, 11, 1t), 9, 3, 5, 4, 3, 2 and 1, remain stationary and the hand winding movement must not be introduced into this gear train. Such introduction is prevented by the provision of the ratchet wheel 14 and the spring pawl 13 on the gear 12; on rotation of the spring stem gear 16, the ratchet wheel 14 turns anti-clockwise so that the nose of the pawl spring 13 can run freely over the ratchet teeth. The friction of the gears and elements 13, 12, 1t), 9, 8, 5, 4, 3 and 1, and their inertia are sufficient to resist the torque exerted during sliding of the pawl spring.

The winding pendulum may be so arranged that it can rotate through a full turn, or if desired, through an arc of less than 360. The mechanism described is effective with any are of rotation of the pendulum.

We claim as our invention:

1. A reversible input unidirectional output gearing comprising a rocker having two intermeshing gears mounted thereon one of which is in constant mesh with a pinion on an oscillating member and the two intermeshing gears being alternately engageable with a gear of the intermediate gearing which is mounted on a fixed axis, and direct action means secured on the rocker engageable with the pinion of the oscillating member for positively moving the rocker on reversal of the oscillating member motion, into a new engagement position.

2. A reversible input unidirectional output gearing comprising a rocker having two intermeshing gears mounted thereon one of which is in constant mesh with the pinion on an oscillating member and the two intermeshing gears being alternately engageable with a gear of the intermediate gearing which is mounted on a fixed axis, the rocker carrying a spring finger secured at one end on the rocker and the other end, being a point which cooperates with the pinion of the oscillating member so that said point during the oscillating movement resiliently rides freely over the teeth of said pinion, While on reversal of the oscillating motion said point engages a tooth gap of the pinion and remains therein until completion of the reverse movement thereby operating the rocker.

3. A reversible input unidirectional output gearing comprising a rocker having two intermeshing gears mounted thereon one of which is in constant mesh with the pinion on an oscillating member and the two intermeshing gears being alternately engageabie with a gear of an intermediate gearing which is mounted on a fixed axis, the rocker. carrying a spring finger secured at one end on the rocker and the other endbeing a point which cooperates with the pinion of the oscillating member so that said point during the oscillating movement resiliently rides freely over the teeth of said pinion, while on reversal of the oscillating motion said point engages a tooth gap of the pinion and remains therein until completion of the reverse movement thereby operating the rocker, and the rocker having two arms each carrying one of the two intermeshing gears and the spring finger is in the form of a spring member attached to the rocker at the end remote from the axes of the gears carried by the rocker.

4. A reversible input unidirectional output gearing comprising a rocker having two intermeshing gears mounted thereon, one of which is in constant mesh with a pinion on an oscillating member and the twov intermeshing gears being alternately engageable with a gear which is mounted on a fixed axis, and direct action means operatively carried by the rocker engageable with the pinion of the oscillating member for positively moving the rocker into anew engagement position upon reversal of movement of the oscillating member.

References (Cited in the file of this patent UNITED STATES PATENTS 

